"As American waistlines have expanded since 1960, so has their consumption of gasoline, say researchers at the University of Illinois at Urbana-Champaign and Virginia Commonwealth University," according to this press release. "The conclusions are based on mathematical computations drawn from data on U.S. weight gain from 1960 to 2002, a period in which the weight of the average American has increased by more than 24 pounds.
Americans are now pumping 938 million gallons of fuel (almost 1 billion!) more annually than they were in 1960 as a result of extra weight in vehicles. And when gas prices average $3 a gallon, the tab for overweight people in a vehicle amounts to $7.7 million a day, or $2.8 billion a year. The numbers are added costs linked directly to the extra drain of body weight on fuel economy."
Watch this interesting graphic of the body mass index in the U.S. increasing from 1985 to 2003.